Merge branch 'bpf-nfp-map-offload'

Jakub Kicinski says:

====================
This set adds support for creating maps on networking devices.  BPF is
programs+maps, the pure program offload has been around for quite some
time, this patchset adds the map part of the equation.

Maps are allocated on the target device from the start.  There is no
host copy when map is created on the device.  Device maps are represented
by struct bpf_offloaded_map, regardless of type.  Host programs can't
access such maps, access is only possible from a program also loaded
to the same device and/or via the BPF syscall.

Offloaded programs are currently only allowed to perform lookups,
control plane is responsible for populating the maps.

For brevity only infrastructure and basic NFP patches are included.
Target device reporting, netdevsim and tests will follow up as well as
some further optimizations to the NFP code.

v2:
 - leave out the array maps, we will add them trivially later to avoid
   merge conflicts with ongoing spectere&meltdown mitigations.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 63 insertions, 2 deletions

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 3496977203a3..5c2c104dc2c5 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -25,6 +25,7 @@ struct bpf_map;
 /* map is generic key/value storage optionally accesible by eBPF programs */
 struct bpf_map_ops {
 	/* funcs callable from userspace (via syscall) */
+	int (*map_alloc_check)(union bpf_attr *attr);
 	struct bpf_map *(*map_alloc)(union bpf_attr *attr);
 	void (*map_release)(struct bpf_map *map, struct file *map_file);
 	void (*map_free)(struct bpf_map *map);
@@ -73,6 +74,33 @@ struct bpf_map {
 	char name[BPF_OBJ_NAME_LEN];
 };
 
+struct bpf_offloaded_map;
+
+struct bpf_map_dev_ops {
+	int (*map_get_next_key)(struct bpf_offloaded_map *map,
+				void *key, void *next_key);
+	int (*map_lookup_elem)(struct bpf_offloaded_map *map,
+			       void *key, void *value);
+	int (*map_update_elem)(struct bpf_offloaded_map *map,
+			       void *key, void *value, u64 flags);
+	int (*map_delete_elem)(struct bpf_offloaded_map *map, void *key);
+};
+
+struct bpf_offloaded_map {
+	struct bpf_map map;
+	struct net_device *netdev;
+	const struct bpf_map_dev_ops *dev_ops;
+	void *dev_priv;
+	struct list_head offloads;
+};
+
+static inline struct bpf_offloaded_map *map_to_offmap(struct bpf_map *map)
+{
+	return container_of(map, struct bpf_offloaded_map, map);
+}
+
+extern const struct bpf_map_ops bpf_map_offload_ops;
+
 /* function argument constraints */
 enum bpf_arg_type {
 	ARG_DONTCARE = 0,	/* unused argument in helper function */
@@ -199,7 +227,7 @@ struct bpf_prog_offload_ops {
 			 int insn_idx, int prev_insn_idx);
 };
 
-struct bpf_dev_offload {
+struct bpf_prog_offload {
 	struct bpf_prog		*prog;
 	struct net_device	*netdev;
 	void			*dev_priv;
@@ -229,7 +257,7 @@ struct bpf_prog_aux {
 #ifdef CONFIG_SECURITY
 	void *security;
 #endif
-	struct bpf_dev_offload *offload;
+	struct bpf_prog_offload *offload;
 	union {
 		struct work_struct work;
 		struct rcu_head	rcu;
@@ -368,6 +396,7 @@ int __bpf_prog_charge(struct user_struct *user, u32 pages);
 void __bpf_prog_uncharge(struct user_struct *user, u32 pages);
 
 void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock);
+void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock);
 
 struct bpf_map *bpf_map_get_with_uref(u32 ufd);
 struct bpf_map *__bpf_map_get(struct fd f);
@@ -377,6 +406,7 @@ void bpf_map_put(struct bpf_map *map);
 int bpf_map_precharge_memlock(u32 pages);
 void *bpf_map_area_alloc(size_t size, int numa_node);
 void bpf_map_area_free(void *base);
+void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr);
 
 extern int sysctl_unprivileged_bpf_disabled;
 
@@ -554,6 +584,15 @@ void bpf_prog_offload_destroy(struct bpf_prog *prog);
 int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
 			       struct bpf_prog *prog);
 
+int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value);
+int bpf_map_offload_update_elem(struct bpf_map *map,
+				void *key, void *value, u64 flags);
+int bpf_map_offload_delete_elem(struct bpf_map *map, void *key);
+int bpf_map_offload_get_next_key(struct bpf_map *map,
+				 void *key, void *next_key);
+
+bool bpf_offload_dev_match(struct bpf_prog *prog, struct bpf_map *map);
+
 #if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL)
 int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr);
 
@@ -561,6 +600,14 @@ static inline bool bpf_prog_is_dev_bound(struct bpf_prog_aux *aux)
 {
 	return aux->offload_requested;
 }
+
+static inline bool bpf_map_is_dev_bound(struct bpf_map *map)
+{
+	return unlikely(map->ops == &bpf_map_offload_ops);
+}
+
+struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr);
+void bpf_map_offload_map_free(struct bpf_map *map);
 #else
 static inline int bpf_prog_offload_init(struct bpf_prog *prog,
 					union bpf_attr *attr)
@@ -572,6 +619,20 @@ static inline bool bpf_prog_is_dev_bound(struct bpf_prog_aux *aux)
 {
 	return false;
 }
+
+static inline bool bpf_map_is_dev_bound(struct bpf_map *map)
+{
+	return false;
+}
+
+static inline struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+static inline void bpf_map_offload_map_free(struct bpf_map *map)
+{
+}
 #endif /* CONFIG_NET && CONFIG_BPF_SYSCALL */
 
 #if defined(CONFIG_STREAM_PARSER) && defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_INET)